Make sure always have cash on hand in Turkey. You never know which shops or restaurants will refuse credit and debit cards. As a general rule: the bigger and more popular the store, the more likely it will accept a card.
Once you open a bank account you can apply for an ATM or debit card. You can use this card to withdraw money from your bank´s ATMs. Theoretically, you should be able to use any Switch, Maestro, or Cirrus card with any ATM in Turkey, but don´t be surprised if you stumble across one (or several dozen) that deny your card.
You will be charged a fee for most ATM transactions. For exact rates and restrictions, check with your bank when you apply for your card.
Be aware that Turkish banks do not allow overdrafts – a safety feature or an annoyance depending on your financial philosophy. Know your account balance to avoid ending up without access to cash or debit funds.
Finally, avoid carrying excessively large amounts of cash, especially if you live in a large city. While the vast majority of Turks are decent and hospitable people, as a foreigner you will stand out to the criminal element.
While debit cards may not work in many shops, you might as well apply for one to withdraw cash from ATMs. If you don´t, you will have to get an ATM card anyway (unless you want to have to visit a bank in person, during its operating hours every time you need cash). Consider any successful debit transactions bonuses.
Credit cards (kredi kartı) are another story. In order to apply for a Turkish credit card you need to have citizenship. As with bank accounts, however, exceptions might be made if banks see you as someone with a lot of money to invest. Know that if you make one of these “back-room” deals, an amount equivalent to your credit limit will usually be frozen in your account as a precaution.
Activating your card usually involves a pitched battle with an automated Turkish-language call centre, during which you will set up your PIN. If you are lucky enough to have the option of doing this via internet, take it. It will save you a migraine-sized headache.
Again, note that while you are theoretically able to use any Switch, Maestro, or Cirrus card in Turkey, you may find reality to be quite different. If you plan on using a foreign bank account in Turkey, check vigorously with your bank to find out whether technical difficulties are likely.
While checks (çek) are used in Turkey, you are best off steering clear of them. In Turkey, you will not be allowed to pay for items with a check and then take them. Rather, you will pay with a check and the shop owner will verify that your check has cleared (during which time your items will be placed on reserve). Only once the check has cleared will you get your merchandise.
Because of the slow process, checks are only used for extremely expensive purchases, or in commercial transactions.
Traveller´s checks are even more inconvenient. Most merchants and banks do not accept them. The banks that do cash traveller´s checks will often force you to visit a specific branch in order to do so. Furthermore, you will be charged a fee for cashing the check (as much as 20% of the check´s value in some cases).
Save yourself the aggravation and stick to cash, debit, or credit instead.